1. Field of the Invention
The present invention relates to a memory storage disk module adapted for use, for example, in a computer memory unit, and including at least one memory storage disk and at least one head able to access the storage disk.
2. Description of the Related Art
Memory storage disk systems, including memory storage disks such as magnetic disks or optical disks, are widely used as external memories of computers. In such a system, a plurality of magnetic disks and cooperating magnetic heads are hermetically housed in a housing, to thus constitute a memory storage disk unit as is well known and disclosed, for example, in U.S. Pat. No. 4,899,237. The magnetic heads are carried by movable arms or the like and are capable of a selective access to a desired magnetic disk. Usually, a control circuit board is attached to the memory storage disk unit, and the memory storage disk unit and the control circuit board constitute a memory storage disk module.
A memory storage disk system of the large computer system comprises a plurality of such memory storage disk modules accommodated in a rack or a cabinet, as disclosed, for example, in U.S. Pat. No. 4,754,397. This patent also discloses power supply units arranged in the cabinet at a lower position thereof. Each module is carried by a drawer slidably accommodated in each shelf of a cabinet.
Japanese Unexamined Patent Publication (Kokai) No. 62-239394 also discloses a memory storage disk system comprising a plurality of memory storage disk modules and power supply units accommodated in a rack or a cabinet. In this publication, each memory storage disk and a cooling fan are housed in a duct-like drawer slidably accommodated in the rack or cabinet. As a cooling fan is provided in the duct-like drawer of each module, the cooling capability for each module can be greatly improved in this memory storage disk system.
Many countries have standards requiring a reduction of electromagnetic noise radiated externally from an electric or electronic device, and to satisfy these standards, manufacturers of memory storage disk systems often provide shields for preventing an emission of electromagnetic waves from the memory storage disk module and associated control circuit board in the rack or cabinet of the electric or electronic device, externally of the rack or cabinet. Therefore, the rack or cabinet for these systems must be made extra large, and thus costly, and accordingly, attempts are being made to produce a rack or cabinet in a smaller and more simple form, to thereby reduce the cost of manufacturing same. Accordingly, there is a need for a rack or cabinet that can be made easily and cheaply, even if each memory storage disk module is a shielded against radiation thereby of electromagnetic waves.
Also, manufacturers of such systems wish to facilitate the assembly work of the memory storage disk system, and accordingly, there is a need for a memory storage disk module having features that will allow manufacturers of these systems to make the rack or cabinet in a more simple manner.